Open standards and the need for public access to information was a strong
message. This became a key component of promoting open office, and open source
software. This posed two problems:

First, those promoting open standards did not stress the importance of having
a fully open source implementation of an office suite. Second, it assumed that Microsoft would stand still and would not react to
this new change in the market.

And that is where the strategy to promote the open source office suite is
running into problems. Microsoft did not stand still. It reacted to this new
requirement by creating a file format of its own, the OOXML....

The Size of OOXML

A common objection to OOXML is that the specification is "too big", that
6,000 pages is a bit too much for a specification and that this would prevent
third parties from implementing support for the standard. Considering that for years we, the open source community, have been trying to
extract as much information about protocols and file formats from Microsoft,
this is actually a good thing.

For example, many years ago, when I was working on Gnumeric, one of the
issues that we ran into was that the actual descriptions for functions and
formulas in Excel was not entirely accurate from the public books you could buy.

OOXML devotes 324 pages of the standard to document the formulas and
functions. The original submission to the ECMA TC45 working group did not have any of
this information. Jody Goldberg and Michael Meeks that represented Novell at the
TC45 requested the information and it eventually made it into the standards. I
consider this a win, and I consider those 324 extra pages a win for everyone
(almost half the size of the ODF standard).

Depending on how you count, ODF has 4 to 10 pages devoted to it. There is
no way you could build a spreadsheet software based on this specification.
...
I have obviously not read the entire specification, and am biased towards what I have seen in the spreadsheet angle. But considering that it is impossible to implement a spreadsheet program based on ODF, am convinced that the analysis done by those opposing OOXML is incredibly shallow, the burden is on them to prove that ODF is "enough" to implement from scratch alternative applications....The real challenge today that open source faces in the office space is that
some administrations might choose to move from the binary office formats to the
OOXML formats and that "open standards" will not play a role in promoting
OpenOffice.org nor open source.

What is worse is that even if people manage to stop OOXML from becoming an
ISO standard it will be an ephemeral victory.

We need to recognize that this is the problem. Instead of trying to bury
OOXML, which amounts to covering the sun with your finger.

I think there is an interesting bit of insight in Miguel's post which I highlighted in red font. IBM and the rest of the ODF opponents lobbied governments against Microsoft's products by arguing that its file formats where not open. However they did not expect that Microsoft would turn around and make those very file formats open and instead compete on innovation in the user experience.

Now ODF proponents like Rob Weir who've been trumpeting the value of open standards now find themselves in the absurd position of arguing that is a bad thing for Microsoft to open up its file formats and provide exhaustive documentation for them. Instead they demand that Microsoft should either abandon backwards compatibility with the billions of documents produced by Microsoft Office in the past decade or that it should embrace and extend ODF to meet its needs. Neither of which sounds like a good thing for customers.